Semiotic Engineering was originally proposed as a semiotic approach to designing user interface languages. Over the years, with research done at the Department of Informatics of the Pontifical Catholic University of Rio de Janeiro, it evolved into a semiotic theory of human-computer interaction. It views HCI as computer-mediated communication between designers and users at interaction time. The system speaks for its designers in various types of conversations specified at design time. These conversations communicate the designers' understanding of who the users are, what they know the users want or need to do, in which preferred ways, and why. The designers' message to users includes even the interactive language in which users will have to communicate back with the system in order to achieve their specific goals. So, the process is in fact one of communication about communication, or metacommunication.
For a quick introduction to de Souza's Semiotic Engineering, we recommend the paper Semiotic engineering: Bringing designers and users together at interaction time (Interacting with Computers 17(3) - Author's copy).
Semiotic engineering has two methods to evaluate the quality of metacommunication in HCI: the semiotic inspection method (SIM) and the communicability evaluation method (CEM). In the 2009 book - Semiotic Engineering Methods for Scientific Research in HCI - Clarisse de Souza and Carla Leitão discuss how SIM and CEM, which are both qualitative methods, can also be used in scientific contexts to generate new knowledge about HCI. To illustrate their points, the authors present an extensive case study with a free open-source digital audio editor called Audacity. They show how the results obtained with a triangulation of SIM and CEM point at new research avenues not only for semiotic engineering and HCI but also for other areas of computer science such as software engineering and programming.
Don Norman has an article about Semiotic Engineering called Design as Communication. You can read it online at: http://www.jnd.org/dn.mss/design_as_communicat.html . He also refers to our approach in another article called Systems Thinking: A Product Is More Than the Product, which can also be read online at: http://www.jnd.org/dn.mss/systems_thinking_a_product_is_more_than_the_product.html
In more than 20 years of research, Semiotic Engineering has expanded its scope, which currently covers research in Culture & HCI (see book by Luciana Salgado and co-authors) and Human-Centered Computing (see book by Clarisse de Souza and co-authors). To celebrate SERG's history and achievements, Simone Barbosa and Karin Breitman have edited a book with a collection of papers by researchers from around the world sharing their views about Semiotic Engineering and Clarisse de Souza's leading role in bringing Semiotics and HCI together.
A Historical Note: René Jorna and Clarisse de Souza independently developed two different kinds of ‘semiotic engineering’. Jorna’s was originally closer to Artificial Intelligence and Cognitive Science. His ideas were later developed and applied to decision support systems and organizational semiotics rather than HCI. The authors were introduced to each other (and to each other's version of 'semiotic engineering') only in 1996, in a Dagstuhl Seminar on Informatics and Semiotics organized by Peter B. Andersen, Mihai Nadin and Frieder Nake.